Law

• When a lower court judge is found to have made an error on a point of law, higher courts (state appeals courts, federal courts and the U.S. Supreme Court) have the power to reverse that judge's decision. If a panel of judges agrees that the lower courts made a bad decision, then it may throw out the conviction. If a reversal occurs on appeal from the trial courts, then a retrial is ordered; otherwise, the convictions are simply thrown out. The power to review decisions is invested in each state by the U. S. Constitution, which allows each state to decide how far these powers will extend. The power of the Supreme Court to hear cases on federal law is also granted by the Constitution.
  
  

Procedure

• Appeals judges can reverse the decisions of judges who made errors of procedure in an earlier trial. A procedural error is a slip-up in courtroom administration. State and Federal appeals courts are made up of three members, while the U.S. Supreme Court has nine. Single judges cannot reverse decisions. For example, if the jury members were not screened properly in the pretrial hearing, then a procedural error was made in jury selection. The effect of a reversal due to procedural error is the same as the effect of a reversal due to legal error: a retrial may be ordered or the convictions may be thrown out.
  
  

Evidence

• In law, the term "evidence" refers to everything from physical evidence to witness testimony. Appeals judges cannot hear new evidence or make judgments about whether evidence heard at trial was valid or not. However, they can "exclude" evidence if it is proven that the decision to admit the evidence at the earlier trial was flawed. For example, if the judge decides that the trial court violated a legal principle when admitting a bloodstained shirt as evidence, the judge can order a new trial in which this evidence will not be heard.
  
  

Result

• Several things can happen when a judge decides that a legal error was made by a lower court. First, he can affirm the decision of the lower court, in which case there is no "reversal." Second, he can order a retrial, in which case the decision is "reversed" (shown to be invalid) and a new trial occurs. Third, he can modify the ruling by throwing out some of the convictions permanently; no new trial is then needed.